Ishim.net



The Story of Blood Group Discovery

[pic]

Submitted by

Abdul Nasser Kaadan, MD, PhD*

** Muhammad Alkhatib

Contents:

- Introduction

- Definition:

- ABO Blood Grouping System

- Rh Factor Blood Grouping System

- Blood Group Notation

- Antigens and Antibodies

- Importance of The ABO System

- Indications for The ABO Grouping

- Dicovery of The ABO System

- ABO Typing

- Characteristics of ABO Antigens

- Characteristics of ABO Antibodies

- ABO Inheritance

- Biochemistry of The ABO System

- Rarest Blood Type:

- Rarest Blood Type in Humans

- Rarest Blood Type in The World

- Early Practices

- Blood Banks

- Clinical Trials

- New Hemoglubin Type Found

- Blood Type Discovery May Lead To New Tools In

HIV Fight

Biography:

- Karl Landsteiner

- Emil Fischer

- James Blundelle

- William Harvey

- Jan Jansky

Introduction:

An adult human has about 4–6 liters of blood circulating in the body. Among other things, blood transports oxygen to various parts of the body. Blood consists of several types of cells floatingaround in a fluid called plasma.

The red blood cells contain hemoglobin, a protein that binds oxygen. Red blood cells transport oxygen to, and remove carbon dioxide from, the body tissues.

[pic]

The white blood cells fight infection.

The platelets help the blood to clot, if you get a wound for example.

The plasma contains salts and various kinds of proteins.

Definition:

The differences in human blood are due to the presence or absence of certain protein molecules called antigens and antibodies. The antigens are located on the surface of the red blood cells and the antibodies are in the blood plasma. Individuals have different types and combinations of these molecules. The blood group you belong to depends on what you have inherited from your parents.

[pic]

There are more than 20 genetically determined blood group systems known today, but the AB0 and Rh systems are the most important ones used for blood transfusions. Not all blood groups are compatible with each other. Mixing incompatible blood groups leads to blood clumping or agglutination, which is dangerous for individuals.

AB0 blood grouping system

According to the AB0 blood group system there are four different kinds of blood groups: A, B, AB or 0 (null).

|[pic] |Blood group A |

| |If you belong to the blood group A, you have A antigens on the surface of your red blood cells and B |

| |antibodies in your blood plasma. |

|[pic] |Blood group B |

| |If you belong to the blood group B, you have B antigens on the surface of your red blood cells and A |

| |antibodies in your blood plasma. |

|[pic] |Blood group AB |

| |If you belong to the blood group AB, you have both A and B antigens on the surface of your red blood |

| |cells and no A or B antibodies at all in your blood plasma. |

|[pic] |Blood group 0 |

| |If you belong to the blood group 0 (null), you have neither A or B antigens on the surface of your |

| |red blood cells but you have both A and B antibodies in your blood plasma. |

Rh factor blood grouping system

| | |

[pic] [pic]

Many people also have a so called Rh factor on the red blood cell's surface. This is also an antigen and those who have it are called Rh+. Those who haven't are called Rh-. A person with Rh- blood does not have Rh antibodies naturally in the blood plasma (as one can have A or B antibodies, for instance). But a person with Rh- blood can develop Rh antibodies in the blood plasma if he or she receives blood from a person with Rh+ blood, whose Rh antigens can trigger the production of Rh antibodies. A person with Rh+ blood can receive blood from a person with Rh- blood without any problems.

[pic]

Blood group notation:

According to above blood grouping systems, you can belong to either of following 8 blood groups:

|A Rh+ |B Rh+ |AB Rh+ |0 Rh+ |

|A Rh- |B Rh- |AB Rh- |0 Rh- |

 

Blood typing:

how do you find out to which blood group soeone belongs?

 1.

You mix the blood with three different reagents including either of the three different antibodies, A, B or Rh antibodies.

2.

Then you take a look at what has happened. In which mixtures has agglutination occurred? The agglutination indicates that the blood has reacted with a certain antibody and therefore is not compatible with blood containing that kind of antibody. If the blood does not agglutinate, it indicates that the blood does not have the antigens binding the special antibody in the reagent.

3.

If you know which antigens are in the person's blood, it's easy to figure out which blood group he or she belongs to!

| | |

What happens when blood clumps or agglutinates?

For a blood transfusion to be successful, AB0 and Rh blood groups must be compatible between the donor blood and the patient blood. If they are not, the red blood cells from the donated blood will clump or agglutinate. The agglutinated red cells can clog blood vessels and stop the circulation of the blood to various parts of the body. The agglutinated red blood cells also crack and its contents leak out in the body. The red blood cells contain hemoglobin which becomes toxic when outside the cell. This can have fatal consequences for the patient.The A antigen and the A antibodies can bind to each other in the same way that the B antigens can bind to the B antibodies. This is what would happen if, for instance, a B blood person receives blood from an A blood person. The red blood cells will be linked together, like bunches of grapes, by the antibodies. As mentioned earlier, this clumping could lead to death.

Blood transfusions: who can receive blood from whom?

Of course you can always give A blood to persons with blood group A, B blood to a person with blood group B and so on. But in some cases you can receive blood with another type of blood group, or donate blood to a person with another kind of blood group.

The transfusion will work if a person who is going to receive blood has a blood group that doesn't have any antibodies against the donor blood's antigens. But if a person who is going to receive blood has antibodies matching the donor blood's antigens, the red blood cells in the donated blood will clump.

[pic]

People with blood group 0 Rh - are called "universal donors" and people with blood group AB Rh+ are called "universal receivers."

Rh+ blood can never be given to someone with Rh - blood, but the other way around works. For example, 0 Rh+ bloodcan not be given to someone with the blood type AB Rh -.

|Blood Group |Antigens |Antibodies |Can give blood to |Can receive |

| | | | |blood from |

|AB Rh - |A and B |None |AB Rh - |AB Rh - |

| | |(Can develop Rh |AB Rh+ |A Rh - |

| | |antibodies) | |B Rh - |

| | | | |0 Rh - |

|A Rh+ |A and Rh |B |A Rh+ |A Rh+ |

| | | |AB Rh+ |A Rh - |

| | | | |0 Rh+ |

| | | | |0 Rh - |

|A Rh - |A |B |A Rh - |A Rh - |

| | |(Can develop Rh |A Rh+ |0 Rh - |

| | |antibodies) |AB Rh - | |

| | | |AB Rh+ | |

|B Rh+ |B and Rh |A |B Rh+ |B Rh+ |

| | | |AB Rh+ |B Rh - |

| | | | |0 Rh+ |

| | | | |0 Rh- |

|B Rh - |B |A |B Rh- |B Rh - |

| | |(Can develop Rh |B Rh+ |0 Rh - |

| | |antibodies) |AB Rh- | |

| | | |AB Rh+ | |

|0 Rh+ |Rh |A and B |0 Rh+ |0 Rh+ |

| | | |A Rh+ |0 Rh - |

| | | |B Rh+ | |

| | | |AB Rh+ | |

|0 Rh - |None |A and B (Can develop |AB Rh+ |0 Rh - |

| | |Rh antibodies) |AB Rh - | |

| | | |A Rh+ | |

| | | |A Rh - | |

| | | |B Rh+ | |

| | | |B Rh - | |

| | | |0 Rh+ | |

| | | |0 Rh - | |

[pic]

|Type |You Can Give Blood To |You Can Receive Blood From |

|A+ |A+  AB+ |A+  A-  O+  O- |

|O+ |O+  A+  B+  AB+ |O+  O- |

|B+ |B+  AB+ |B+  B-  O+  O- |

|AB+ |AB+ |Everyone |

|A- |A+  A-  AB+  AB- |A-  O- |

|O- |Everyone |O- |

|B- |B+  B-  AB+  AB- |B-  O- |

|AB- |AB+  AB- |AB-  A-  B-  O- |

| | | |

Blood donation possibilities

ANTIGENS AND ANTIBODIES

[pic]

[pic]

Blood group system

A series of antigens exhibiting similar serological and physiological characteristics, and inherited according to a specific pattern.

Importance of the ABO system:

This is the only blood group system in which antibodies are consistently, predictably, and naturally present in the serum of people who lack the antigen. Therefore  ABO compatibility between donor and recipient is crucial since these strong, naturally occurring A and B antibodies are IgM and can readily activate complement and cause agglutination.  If ABO antibodies react with antigens in vivo, result is acute hemolysis and possibly death.

Indications for ABO grouping:

ABO grouping is required for all of the following individuals:

• Blood Donors:since it can be life threatening to give the wrong ABO group to the patient.

• Transfusion recipients: since we need to know the donor blood is ABO compatible.

• Transplant Candidates and Donors: ABO antigens are found in other tissues as well.  Therefore the transplant candidates and donors must be compatible.

• Prenatal Patients: To determine whether the mothers may have babies who are suffering from ABO-HDN.  It is also beneficial to know the ABO group should she start hemorrhaging.

• Newborns: If the baby is demonstrating symptoms of Hemolytic Disease of the Newborn, the ABO group needs to be determined along with Rh and others.

• Paternity testing:Since the inheritance of the ABO Blood Group System is very specific, this serves as one of the first methods to determine the likelihood that the accused father is the father or not.

Discovery of the ABO system:

In 1900 Karl Landsteiner reported a series of tests, which identified the ABO Blood Group System.  In 1910 he won Nobel prize for medicine for this discovery.  He mixed the serum and cells of all the researchers in his lab and found four different patterns of agglutination.  From those studies he developed what we now know as Landsteiner's rules:

1. A person does not have antibody to his own antigens

2. Each person has antibody to the antigen he lacks (only in the ABO system)

|Incidence (%)  of ABO Blood Groups in the US Population |

|ABO Group |Whites |Blacks |

|O |45 |49 |

|A |40 |27 |

|B |11 |20 |

|AB |4 |4 |

ABO Typing

ABO typing involves both antigen typing and antibody detection.  The antigen typing is referred to as the forward typing and the antibody detection is the reverse typing

• The forward typing determines antigens on patient's or donor's cells

a. Cells are tested with the antisera reagents anti-A, anti-B, (and in the case of donor cells anti-A,B)

b. Reagents are either made from hyperimmunized human sources, or monoclonal antibodies. 

c. One advantages of the monoclonal antibodies are the antibody strength.

d. Another advantage of monoclonals: human source reagents can transmit infectious disease (hepatitis).

• Reverse typing  determines antibodies in patient's or donor's serum or plasma

a. Serum tested with reagent A1 cells and B cells

b. Reverse grouping is also known as backtyping or serum confirmation

|Routine ABO Typing |

|Reaction of Cells Tested With |Red Cell ABO Group |Reaction of Serum Tested Against |Reverse ABO |

| | | |Group |

|Anti-A |Anti-B |  |A1 Cells |B Cells |  |

|0 |0 |O |+ |+ |O |

|+ |0 |A |0 |+ |A |

|0 |+ |B |+ |0 |B |

|+ |+ |AB |0 |0 |AB |

Discrepancies in ABO typing

1. Results of forward and reverse typing must agree before reporting out blood type as seen in the about table.

2. If forward and reverse do not agree, must identify cause of discrepancy.

3. If cannot resolve discrepancy, must report out blood type as UNKNOWN and give group O blood

Characteristics of ABO antigens:

ABO antigens are glycolipid in nature, meaning they are oligosaccharides attached directly to lipids on red cell membrane.  These antigens stick out from red cell membrane and there are  many antigen sites per red blood cell (approximately 800,000)

Besides their presence on red blood cells, soluble antigens can be present in plasma, saliva, and other secretions.  These antigens are also  expressed on tissues other than red cells.  This last fact is important to consider in organ transplantation.

ABO antigens are  only moderately well developed at birth.  Therefore ABO-HDN not as severe as other kinds of Hemolytic Disease of the Newborn.

Characteristics of ABO antibodies:

1. These are expected naturally occurring antibodies that occur without exposure to red cells containing the antigen.  (There is some evidence that similar antigens found in certain bacteria, like E.coli, stimulate antibody production in individuals who lack the specific A and B antigens.)

2. Immunoglobulin M antibodies, predominantly

3. They react in saline and readily agglutinate. Due to the position of the antigen and the IgM antibodies it is not necessary to overcome the zeta potential.

4. Their optimum temperature is less than 30oC, but reactions do take place at body temperature

5. Not only are these antibodies expected and naturally occurring, they are also commonly present in high titer, 1/128 or 1/256.

6. They are absent at birth and  start to appear around 3-6 months as result of stimulus by bacterial polysaccharides.  (For this reason, newborn blood is only forward typed.)

ABO INHERITANCE

Inheritance Terminology:

gene: determines specific inherited trait (ex. blood type)

chromosome: unit of inheritance. Carries genes.23 pairs of chromosomes per person, carrying many genes. One chromosome inherited from mother, one from father

locus: site on chromosome where specific gene is located

allele: alternate choice of genes at a locus (ex. A or B; C or c, Lewis a or Lewis b)

homozygous: alleles are the same for any given trait on both chromosome (ex. A/A)

heterozygous: alleles for a given trait are different on each chromosome (ex. A/B or A/O)

phenotype: observed inherited trait (ex. group A or Rh positive)

genotype: actual genetic information for a trait carried on each chromosome (ex. O/O or A/O)

dominant: the expressed characteristic on one chromosome takes precedence over the characteristic determined on the other chromosome (ex. A/O types as A)

co-dominant: the characteristics determined by the genes on both chromosomes are both expressed - neither is dominant over the other (ex. A/B types as AB)

recessive: the characteristic determined by the allele will only be expressed if the same allele is on the other chromosome also (ex. can type as O only when genotype is O/O)

ABO Genes

The A and B genes found on chromosome #9.  We inherit one gene (allele) from our father and one from our mother.  The two co-dominant alleles are A or B.  Anytime an individual inherits an A or B gene it will be expressed.

The O gene signifies lack of A or B antigens.  It is not expressed unless this gene is inherited from both parents (OO).  Therefore the O gene is recessive.  

Below is the example of two individuals who are A.  One inherited only one A gene along with an O gene and is therefore heterozygous.  The other inherited 2 A genes and is homozygous for A.

|[pic] |

|1 =  A/A           |           2 = A/O |

|1 = Homozygous A |2 = Heterozygous A |

|Phenotype A |Phenotype A |

|Genotype A/A |Genotype A/0 |

|Can Contribute Only an  A Gene to Offspring |Can Contribute A or O Gene to Offspring |

Inheritance Patterns

We can't determine genotypes of A or B people unless family studies are done.  Some basic rules of  ABO inheritance are as follows:

1. A/A parent can only pass along A gene

2. A/O parent can pass along either A or O gene

3. B/B parent can only pass along B gene

4. B/O parent can pass along either B or O gene

5. O/O parent can only pass along O gene

6. AB parent can pass along either A or B gene

ABO phenotypes and genotypes

1. Group A phenotype = A/A or A/O genotype

2. Group B phenotype = B/B or B/O genotype

3. Group O phenotype = O/O genotype

4. Group AB phenotype = A/B genotype

Offspring possibilities

Possibilities of an A/O mating with a B/O: (Children's genotypes in purple)

|Mother's Genes |Father's Genes |

| |B |O |

|A |AB |AO |

|O |BO |OO |

Possibilities of AA mating with BB: (Children's genotypes in purple)

|Mother's Genes |Father's Genes |

| |B |B |

|A |AB |AB |

|A |AB |AB |

Possibilities of an A/A mating with a B/O: (Children's genotypes in purple)

|Mother's Genes |Father's Genes |

| |B |O |

|A |AB |AO |

|A |AB |AO |

Possibilities of an A/A mating with an O/O:

|Mother's Genes |Father's Genes |

| |O |O |

|A |AO |AO |

|A |AO |AO |

Possibilities of an A/O mating with an O/O:

|Mother's Genes |Father's Genes |

| |O |O |

|A |AO |AO |

|O |OO |OO |

Possibilities of an A/B mating with a O/O:

|Mother's Genes |Father's Genes |

| |O |O |

|A |AO |AO |

|B |BO |BO |

BIOCHEMISTRY OF THE ABO SYSTEM

The ABO antigens are terminal sugars found at the end of long sugar chains (oligosaccharides) that are attached to lipids on the red cell membrane. The A and B antigens are the last sugar added to the chain.  The "O" antigen is the lack of A or B antigens but it does have the most amount of next to last terminal sugar that is called the H antigen.

[pic]

Production of A, B, and H antigens

The production of A, B and H antigens are controlled by the action of transferases.  These transferases are enzymes that catalyze (or control) addition of specific sugars to the oligosaccharide chain. The H, A, or B genes each produce a different transferase, which adds a different specific sugar to the oligosaccharide chain.

To understand the process let's look at the sequence of events:

1. Precursor chain of sugars is formed most frequently as either Type 1 or Type 2 depending on the linkage site between the N-acetylglucosamine (G1cNAc) and Galactose (Gal).

[pic]

2. H gene causes L-fucose to be added to the terminal sugar of precursor chain, producing H antigen (shown in this diagram of a Type 2 H antigen saccharide chaine).

[pic]

3. Either A gene causes N-acetyl-galactosamineto be added to H substance, producing A antigen, (shown in this diagram) or

[pic]

4. B gene causes D-galactose to be added to H substance, producing B antigen.

[pic]

5. If both A and B genes present, some H-chains converted to A antigen, some converted to B antigen.

6. If H gene absent, no H substance can be formed, and therefore no A or B antigen. Result is Bombay blood group.

Bombay blood group:

The Bombay blood group lacks H gene and therefore cannot make H antigen (H substance).  Since the H substance is the precursor for the A and B antigens, these antigens also are not made.  The cells type as O and the serum has anti-A, anti-B, and anti-H since the individual lacks all of these antigens.   Anti-H agglutinates O cells.  The only cells  Bombay individuals do not agglutinate are from other Bombay blood people since they lack the H antigen,

Subgroups of A and B

The subgroups of A and B are caused by decreased amounts of antigen on the red blood cells.  They are inherited conditions. The most common are subgroups of A. Approximately 80% of the A's and AB's have a normal expression of A1.  Most of the other 20% are either A2  or A2B.  This subgroup has fewer H chains converted to A antigen – result is more H chains on red cell, and fewer A antigens.  A small percentage of the individuals

[pic]

There are other, weaker subgroups of A exist: A3; Aint; Am, Ax; Ael.  Each has a different pattern of reacting with anti-A, anti-A, and various antibody-like substances called lectins. 

Lectins

Lectins are extracts of seeds of plants that react specifically with certain antigens.  The two most common lectins used in Blood Bank are:

• Ulexeuropaeus, or lectin H, which agglutinates cells that have H substance.

• Dolichosbiflouros, or lectin A1, which agglutinates cells with A1.

Lectin-H reacts strongest with O cells, which has a high concentration of H antigen, and weakest with A1 cells, which have a low concentration of H.

|Lectin |O cells |A2 cells |A2B cells |B cells |

|Reaction with anti-A,B |4+ |4+ |mf |2+ |

|Reaction with Lectin-A1 |4+ |0 |0 |0 |

|Reaction with Lectin-H |0-w |1-2+ |2+ |2-3+ |

|Presence of anti-A1 |no |may |may |often in serum |

Problems with Ax:

Because Ax cells initially type as O and serum usually has anti-A1, (along with anti-B), patient forwards and reverses as O. Unfortunately when Ax is transfused into an O individual, the naturally occurring anti-A,B will react with the donor cells causing a transfusion reaction.  Therefore: To prevent Ax from being erroneously typed as O, confirm all group O donors with anti-A,B.

Rarest Blood Type

[pic]

Rarest Blood Type in Humans:

The Australian scientist Karl Landsteiner was the first person to come up with the discovery of ABO blood group system. He was given the Nobel Prize in Physiology or Medicine in 1930 for this path breaking discovery. However, Landsteiner discovered A, B and O blood type. The fourth blood type explained in 1902 was carried out by Alfred von Decastello and Adriano Sturli.

It was found O is the most commonly found blood type. But, what is the rarest blood type in the world? The following blood types chart will help you understand and find the rarest blood type in the world.

|Blood Type and Rh |Frequency |Number of People Found ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download